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T i m T i m is offline
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Default Metal maths help please.

Hi All,

I would be interested in some technical feedback to a mechanical
project if anyone is in a engineering / mathematical mood please?

Project: 'Upgrading' an old RAC take-down motorcycle (carrying)
trailer to deal with what looks like a few years of neglect.

Plan: Replace the 950 long by 60 x 60 x 3 mm 'steel' box section cross
member (that carried the suspension units inside the box) with a 1150
long by 50 x 50 x 5 mm steel cross member (with conventional
suspension units on the underside of the box).

If we assume the wheel track of both is plus another 2 x 100 mm then
we have a beam of 60 x 60 at 1250 and the 50 x 50 at 1350 long (I'm
making it a bit wider to help the stability).

So, what I think I want to know is what sort of weight would I be able
to suspend on the middle, ignoring any torsional or other loads and
that the steels are the same and typical for this sort of role etc
please?

FWIW the 'load' is currently spread over about 180 mm at the middle of
the cross member (the backbone of the chassis if you like), if that
makes any difference (and I guess it might). ;-)

Thanks for your time.

T i m